Dynavector P75 Mk4

Hardware Review

Dynavector P75 Mk4

Thursday, February 8, 2018

MM/MC phono stage

Jason Kennedy

If you play a competitive sport at almost any level you will become aware that there are people who are better than you and others who are better than them, and so it goes until you get to Roger Federer. There are almost limitless gradations between beginners and champions, yet at every level of ability the difference between players is apparently quite wide. This seems to be the case with phono stages, prices start at under £50 and go up to the tens of thousands and each step is a large one, this is because the output of a moving coil cartridge is tiny and immensely rich and the potential to lose some of that information is clearly quite large. Dynavector makes moving coil cartridges in Japan and amplifiers including phono stages in Australia, so its engineers should know what it takes to build a good example of the latter.

They only make one phono stage however, a mid market model, while the cartridge range extends to the high end. This stage, called the P75, has just entered its fourth incarnation in 14 years. The main change over the Mk3 is the casework which is much more attractive than it was, the P75 remains compact at 4.6cm (less than two inches) high but has an extruded aluminium chassis with a glass and metal front plate through which a red backlit logo shows when it’s on. On the back are the usual in and outputs plus earth point, the latter an attractive rounded square with gold plating and the DV logo that helps to make up for the price/size ratio. Power is derived from an external supply but there is a power switch on the rear which is unusual in components of this size where it’s often necessary to remove the mains plug to turn them off.

You might notice the four bolts that hold aluminium lugs on either side at the back, remove these bolts and the associated metalwork and you can slide off the black section of the case. This gives access to an array of pins that can be connected with supplied jumpers to alter gain and load impedance, or if you want to go deeper, be used to instigate what Dynavector calls Phono Enhancer (PE) mode. In this arrangement the loading is not based on what the cartridge manufacturer recommends using impedance settings from 33 Ohms to 47kOhms but on the internal resistance of the moving coil itself. In PE mode the P75 operates as a current amplifier rather than a voltage amp, where instead of a certain impedance the cartridge ‘sees’ a short circuit with zero resistance, this forces it to emit a current through the arm and tonearm cables that the amplifier converts into a voltage prior to amplification. This sounds odd but in practise extracts a perceived increase in level signal from the cartridge. But this depends on the resistance of the cables between cartridge and stage as well as the coils themselves, so results will vary from one set up to another, Dynavector states “PE Mode would cause an increase the linearity of the magnetic field inside the cartridge and this can improve the sound quality”, they don't suggest that it will increase output.

The settings offered range from 4 – 10 Ohms to 20 – 50 Ohms in three stages and can be used with any moving coil, but its success depends on the quietness of the magnetic circuit and the aforementioned cabling. Apparently some cartridges may saturate easily and struggle to provide enough current at musical peaks. Under the skin the main change to the Mk4 is in the power supply which is a new ultra low noise high frequency switching type, which claims to have “virtually immeasurable” noise levels and converts the incoming 12V (from a wall-wart) into dual high voltages. A smaller but sometimes useful addition is that capacitance settings can now be changed or replaced with the capacitor of your choice being soldered into the board.

Sound qualityI started off using the P75 Mk4 with a Rega Apheta 2 on a Rega RP8 turntable and set the stage up for the standard 100 Ohm impedance recommended for this cartridge. It sounded good, bouncy, vibrant and tight with open vocals and lovely groove. Saxophone worked really nicely with strong image presence and multiple layers opening up and revealing all the goodness of the various tracks. It’s not as vital and clearcut as the Tom Evans Microgroove X which brings out more of the richness of each recording, but that’s a pricier stage with none of the adjustability on offer with the Dynavector. The P75 Mk4 is always enjoyable thanks to good timing and strong bass allied to good low level resolution, the fingers on tabla of Patricia Barber’s ‘Constantinople’ are very finely resolved and contrast superbly with the tension produced by the electric guitar.

Shifting over to PE mode in its 4 – 10 Ohm middle setting (the Apheta has a 10 Ohm coil resistance) brought about an increase in dynamics and gain which projected the sound into the room more effectively. The sound escaped the speakers more easily and the thrapping of the acoustic guitar on Joni Mitchell’s ‘The Wolf that Lives in Lindsey’ (Mingus) where the attack and decay were very well served. The focus and low level detail were likewise very strong, it’s a clear-cut sound that delivers good resolution for the money. Accessing the slightly fiddly jumpers once more I upped the PE setting to the 20 – 50 Ohm position which increased the output level significantly and provided better dynamics in the process. Vocals were really well projected and the bass drums on Tom Waits’ ‘Underground’ (Swordfishtrombones) had really big dynamics. It wasn’t the most comfortable of sounds however, and didn’t encourage higher level listening so I tried the middle PE setting, which as Goldilocks discovered, was just right.

Now there was more than enough gain but in the context of a relaxed presentation that could be played back at any level in comfort and provided a superb result all round. As good a time as any to try another cartridge I thought, this time it was a Dynavector, the XX2 MkII which is a £1,000 or thereabouts and has alnico magnets and a boron cantilever. It’s specified coil resistance is six Ohms so I switched the jumpers over to the low setting and let it roll. It gave a similar level of output to the Apheta 2 set at medium PE, it sounded juicy and warm with nice timing and lovely phat bottom end after the Rega. It’s not smoothed off in the treble, there’s plenty of sparkle with bells for instance, but the top end is relaxed and sweet, especially when it comes to operatic voice where the big spacious sound is fluid, dynamic and even majestic with the right work.

Using this cartridge I once again made the comparison with a Microgroove X and got a slightly more revealing and live sound at a similar output level that brought out the tonal luxury of the records that the XX2 traced. I also compared this with a Chord DAVE DAC and the Innuos SE server and was surprised to hear a more relaxed presentation but one with less vitality that failed to keep me interested for long. With music that was made for vinyl, such as Joni Mitchell’s Court and Spark, it seems almost impossible for digital systems to compete in the long run.

The P75 Mk4 is a bit more pricey than it used to be, what isn’t, but it delivers sound quality that’s fully commensurate with that asking price. What’s more it’s a great partner for any cartridge not just those from the same company as the Apheta 2 proves, especially when you set it up in PE mode which is undoubtedly it’s strongest suit.